Numerical study on three-dimensional CJ detonation waves interacting with isotropic turbulence

The three-dimensional structures of a cellular detonation wave interacting with different turbulent flows were investigated using a one-step irreversible Arrhenius kinetics model. High-resolution bandwidth-optimized WENO scheme of spatial discretization and total variation diminishing temporal integration are used to solve the three dimensional chemically reactive Navier-Stokes equations. The turbulent vertical and entropic forcing effects on the three dimensional detonation wave structures and dynamics are analyzed, as well as the detonation effects on turbulent vortex structures. It has been found that the turbulence field imposed has created small scale wrinkles embedded in the detonation front, apart from the large scale features of detonation without turbulence. The detonation propagating velocity over the leading shock front varies from 0.8 to 1.6 times of CJ velocity and its probability density function (pdf) skews towards sub-CJ velocity and peaks at about 0.9. The recorded detonation velocity always preferentially decays with time, with very rapid accelerations through triple point interactions. Its pdf also skews to sub-CJ velocity, while its overall shape agrees well with V-3. The reaction zone is greatly influenced by the vortex, much more irregular and elongated for the turbulent cases. Distributed burning pockets are more likely to be found there. The turbulent kinetic energy is amplified across the detonation, and periodically oscillates downstream the detonation. The off-diagonal components of Reynolds stress also show a rapid rise across the detonation and present to be non-zero downstream of detonation. Vortex structures are compound results of the convected vortex and the generated vortex by the collision of triple points. The convection term and baroclinic generation term in the transport equation of enstrophy are compared in detail.